in all of these stages, and consequently express the action of imbibition and osmosis. The distinct action of imbibition and the later joint action of hydration by osmosis and by imbibition may be most readily recognized, in organs in which the region of growth is generalized as in the ovate flattened joints of Opuntia or in such globular fruits as the tomato. The measurement of the growth of one of these joints may be begun when it has a lateral area no larger than the thumbnail, and during this stage the increase is rapid and shows a minimum disturbance from changes in external conditions, as shown by the illustrations. Growth continues throughout the entire mass until an advanced stage of development is reached, when it first slackens in the basal portion. By this time large vacuoles have been formed in the thin-walled cells, and water loss from the surfaces of the organ has reached such a rate that great daily variation in the volume results and actual shrinkage may ensue. A similar history may be predicated for such structures as the large berry-like fruit of the tomato, it being noted that the material in both illustrations takes on solid matter and water at such rate that not much alteration in their proportions occurs during development. The enlargement of the trunk of a tree results from the multiplication and growth of cambium and other cells on the outside of the trunk directly inside and covered by the bark. The trunk of the tree is in effect a cylinder of moist but dead woody tissue surrounded by a living sheath which becomes very active at some time in the year and which as a result forms an additional layer or sheet of wood on the trunk which in cross section gives the appearance which has caused it to be designated as an annual ring of growth. The actual course of growth or formation of these annual cylinders or, more strictly speaking, cones, has not until recently been measured. In 1918 I was successful in making a working model of a dendrograph which might be attached to the trunk of a tree in such manner that its changes in volume due to whatever causes were traced on a ruled sheet of paper carried by a revolving drum. The essential part of this apparatus is a yoke of metal, which has two bearing screws resting on the trunk and carrying a third contact point on the end of the pen lever. It was not possible to make a practicable instrument until a yoke could be constructed which showed but little variation as a result of changes in temperature. Three alloys with a very low temperature coefficient, bario C., manganin and invar have been used and dendrographs are now in operation on the trunks of two species of pine, and oak, an ash, a sycamore and a beech tree, and as these instruments were placed in position before growth began in 1919, there is every prospect that seasonal records will be obtained from which the principal features of growth may be seen. Weekly records show that these trees do not behave alike and that many conditions are to be considered in interpreting the records. It is evident for example that but little is known concerning the properties of bark as a water-proofing or protecting coat for the tree. The loose bark of the ash and pine trees seems to allow such a great water loss from the surface during the mid-day period as to cause actual shrinkage which does not occur in trees such as the beech and live-oak, which have a perfect living green outer bark or skin. The facts disclosed by these records can not fail to be of interest in a discussion of any phase of the complicated problem of the ascent of sap. D. T. MACDOUGAL DESERT BOTANICAL LABORATORY JOSEPH BARRELL AMERICAN geology has lost one of its foremost leaders, one who promised to stand as high as the highest. Professor Barrell's other colleagues will undoubtedly agree with Professor T. C. Chamberlin when he says: "We had come to look upon him as one of the most promising leaders in the deeper problems of earth science. We feel that his early departure is a very sad loss to our profession not only, but to the whole group of sciences that center in the earth and its constitution." Only a few days before his death there came to him the news of the highest honor that can be given to an American scientist, election to the National Academy of Sciences. His election, furthermore, was by a unanimous vote of the academicians present at the April meeting in Washington, and such a vote is rare in the academy. He This Joseph Barrell, the son of a farmer, was born at New Providence, N. J., December 15, 1869, and died of pneumonia and spinal meningitis in New Haven on May 4, 1919. leaves a wife and four sons. Standing 5 feet 10.5 inches in height, of the blue-eyed Nordic type, with a full head of wavy light-brown hair, he was spare and slender in build, but characterized by great muscular strength in comparison to body weight. He was of the eighth American generation from the Puritan George Barrell, who migrated from Suffolk, England, and settled at Boston in 1637. first American Barrell began as a cooper, but most of his descendants have been sea-going people and shipping merchants. The most widely known and wealthiest was Joseph Barrell of Boston, after whom the subject of our sketch, his great-grandson, was named. This Joseph Barrell is said to have "early espoused and firmly maintained the cause of his country," and for a time represented the town of Boston in the State Legislature. It was in his splendid home that General George Washington was entertained during his visit to Boston. Professor Barrell received the first part of his collegiate education at Lehigh University, taking in due course its B.S., E.M. and M.S. degrees, and in 1916 this institution gave him its doctorate of science. From 1893 to 1897 he was instructor in mining and metallurgy at his alma mater, and then was given leave of absence to go to Yale for graduate studies in geology, taking his Ph.D. degree in 1900. Returning to Lehigh, he was made assistant professor of geology, and for three years taught not only geology but zoology as well. In 1903 he was called to Yale as assistant professor of geology and in 1908 promoted to the chair in structural geology. In the geological department at Yale he was a unifying force and a tower of strength. During the summer months from 1893 onward, Barrell spent nearly all the time in the field, working at first as an engineer in the coal mines of Pennsylvania, then in the mines of Butte, Montana, devoting one summer to the geology of southern Europe, and later studying widely the geology of the Appalachians and of the New England States. Professor Barrell's first publications, in 1899 to 1900, deal with mining, but since 1901 nearly all his work has been in geology. His bibliography has upward of forty-five titles, totalling more than 1,500 pages. Several articles remain unpublished, at least two of which it is hoped to print during this year. A more detailed account of his life and work will appear in an autumn number of the American Journal of Science. Barrell's most important work has to do with the strength of the earth's crust. The series of papers bearing that title examine into "the mechanics of the earth considered as a body under stress, owing to the variation in density and form which mark its outer shell." He was all the more able to handle this most difficult subject because of his thorough training in engineering at Lehigh. His last work along this line will be published this fall. From the manuscript we learn that "The larger features of the earth's surface are sustained in solid flotation, and at some depth the strains due to the unequal elevations largely disappear, the elevations being compensated by variations of density within the crust. In consequence, the subcrustal shell is subjected to but little else than hydrostatic pressure." Isostatic balance is, however, not everywhere in adjustment, but the adjustments are held to be irregular and imperfect in distribution and mostly concentrated in the outer one hundredth of the earth's radius, with a tendency to progressively disappear with depth. On the other hand, "the outer crust is very strong, capable of supporting individual mountains, limited mountain ranges, and erosion features of corresponding magnitude." Barrell also did much toward working out the criteria by which the climates, marine deltas and geographies of the geologic past may be discerned in the sediments or stratified rocks that make up the greater portion of the geologic record. This work brings out especially the importance in earth history of the ancient formations laid down upon the lands by the fresh waters and the wind, in contradistinction to those deposited by the seas and oceans. The length of geologic time was another problem that deeply interested Barrell. In his "Rhythms and the Measurements of Geologic Time," he came to the conclusion that through the rhythmic oscillations of the terrestrial processes which the earth has undergone, its age is many times greater than even geologists in general have imagined-in fact, that it is of the order of about 1,500 million years. A fourth line of research which occupied Barrell was the origin and genesis of the earth, and here he extended in modified form the Chamberlin-Moulton planetesimal hypothesis, i. e., that the planets and their moons arose out of the sun during a time of induced tidal disruption. Some of his best work was to develop along this line, and an extensive manuscript on The Genesis of the Earth" is ready for publication. Since 1913, Barrell has on a number of occasions taken opportunity to point out that the supposed Mesozoic peneplain of southern New England was in reality "stairlike or terraced in its character, facing the sea, and bore the marks of ultimate control by marine denudation. These terraces [more than five in number] are now dismantled by erosion except in regions favored by the presence of broadly developed resistant rock structures. . . . All are regarded as younger than the Miocene." With this view, he adds, we get "a suggestion of the geological rapidity of completion of an erosion cycle in a region near the sea and of a sequence of diastrophic rhythms there recorded." Here too there is considerable manuscript that will be published later on. Finally, the evolutionary problems connected with paleontology claimed his interest, and he has presented evidence to show that fishes probably arose in the early Paleozoic in the fresh waters of the lands, and thence migrated to the seas. Also that lungs developed out of air-bladders in water-breathing animals caught in recurrent epochs of semiaridity. Such great environmental changes brought about the necessity for change from a water habitat to seasonal dry ones, and hence "the piscine fauna which endured these conditions came through profoundly changed." The primitive sharks of Silurian time, having no air-bladder, " were driven to the seas. The fresh-water fishes which remained were ganoids and dipnoans, fishes with air-bladders efficient for the direct use of air." Finally, from crossopterygian ganoids, under the stimulus of the semiaridity of the Devonian, there emerged the amphibians, able to carry forward their activities as terrestrial animals. Similarly, he held that man was brought to his present high physical and mental state not merely as the "product of time and life," but that he is "peculiarly a child of the earth and is born of her vicissitudes." The changing climates during the Pliocene and Pleistocene, acting upon the vegetation of these times, caused the prevalent forests of Asia, he thinks, to dwindle away, producing "a rigorous natural selection which transformed an ape, largely arboreal and frugivorous in habits, into a powerful, terrestrial, bipedal primate, largely carnivorous in habit, banding together in the struggle for existence, and by that means achieving success in chase and war. The gradual elimination, first of the food of the forests, lastly of the refuge of the trees, through increasing semiaridity, would have been a compelling cause as mandatory as the semiaridity which compelled the emergence of vertebrates from the waters, transforming fishes into amphibians." YALE UNIVERSITY CHARLES SCHUCHERT SCIENTIFIC EVENTS THE SOLAR ECLIPSE1 TELEGRAMS received by the Astronomer Royal report that at the station at Sobral, in Brazil, occupied by Dr. Crommelin and Mr. 1 From Nature. Davidson for photographing the field of stars round the sun on the occasion of the total eclipse of the sun last week (May 29), the sky was clear for at least part of totality, and that the program was satisfactorily carried out. The photographs have been developed, and all the stars expected are shown on the plates taken with the astrographic lens, as well as on those taken with a second telescope lent by Father Cortie. The expedition will remain at Sobral until the necessary comparison photographs are taken in situ. The message from Professor Eddington at Prince's Island, off the coast of West Africa, which reads "Through cloud, hopeful," may be taken to imply that some success will also be derived from the work of this expedition. It will be remembered that Professor Eddington and Mr. Cottingham were provided with the 13-inch object-glass of the astrographic telescope of the Oxford University Observatory, whilst the observers in Brazil had the similar object-glass from Greenwich, and that the program of both stations was to take photographs of the stars that surrounded the sun, of which there are at least twelve within 100 of the sun's center of photographic magnitude ranging from 4.5 to 7.0, for the purpose of testing Einstein's relativity theory of gravitation, and also the hypothesis that gravitation, in the generally accepted sense, acts on light. Photographs that have been taken during the eclipse will be compared with others that have been, or will be, taken of the same stars in the night sky to detect any displacement that may be considered to be due to the presence of the sun in the field. There is at present no information as to the type of the corona, and apparently few observing parties have been organized to make observations to record this. From a note in the daily press last week, said to emanate from the Yerkes Observatory, it seems not unlikely that a large prominence may have been on the limb of the sun at the time of the eclipse. It had been announced that the Cordoba Observatory would dispatch an expedition to Brazil, and that possibly Professor Abbot, of the Smithsonian Institution, would proceed to La Paz, Bolivia, where the eclipse happened at sunrise, with coronal cameras and with instruments for measuring the sky radiations by day and night, but it is too early to have heard of any results of such observations. Also it has been announced that Professor D. P. Todd would take photographs of the eclipse from an aeroplane at a height of 10,000 feet from the neighborhood of Monte Video, where the eclipse would only be partial. REVISTA MATEMATICA HISPANO-AMERICANA UNDER the above title a new mathematical periodical began to appear at the beginning of the present year, which may be of some general scientific interest both on account of territory covered by its title and also on account of some of its unique aims. One of these is the publication of corrections of errors found anywhere in the mathematical literature. These corrections are to appear in a special section headed Glosario Matematico. While mathematics is an exact science its literature is by no means free from different types of errors, varying from slight oversights to those relating to matters of fundamental importance. The majority of these errors are readily recognized by the careful reader and need only to be pointed out to be acknowledged; but, as mathematics grades gradually into various inexact sciences -such as philosophy, history and physics-it is clear that a part of its literature relates to the eternal approximations towards an unstable limit and here the question of errors connects up with endless words. The corrections in the Revista, published at Santa Teresa, 8, Madrid, Spain, are supposed to be confined to the former type of errors and these corrections may serve the double purpose of curtailing the repetition of such errors and of pointing out somewhat slippery ground in mathematical fields. It is also of interest to walk securely over ground where experts slipped by overlooking lurking dangers which their slipping caused to change to wellmarked pitfalls. General interest in this new mathematical periodical may perhaps be enlisted by the can did manner in which the unfavorable mathematical situation among the Spanish-speaking people is depicted in a short note appearing in the first number of this journal. The comparatively slight contributions made by these people along the line of mathematical research stands in great contrast with the large advances made by the people living immediately north of Spain. One of the most important steps towards the remedy of an unfortunate public situation is to exhibit the great need of such a remedy. It is hoped that the present journal may be successful in this direction and also in awakening interest in a field which is so fundamental for the further scientific development of the people using the Spanish language. The editor of the journal is J. Rey Pastor. G. A. MILLER EXPEDITIONS OF THE CALIFORNIA ACADEMY OF SCIENCES MISS ALICE EASTWOOD, curator of botany, of the California Academy of Sciences, has just returned from a three months' study of the flora of Arizona and New Mexico. Miss Eastwood's special mission was to collect trees and shrubs but chiefly cottonwoods for Professor C. S. Sargent of the Arnold Arboretum in connection with the revision of his Trees of North America. At the same time Miss Eastwood made important additions to the herbarium of the academy. The academy is undertaking exploration work this summer in lower California. Mr. Joseph R. Slevin, assistant curator of the department of herpetology, sailed on June 14 on the steamer Alliance for La Paz, Mexico, with the purpose of investigating the reptiles and amphibians of the cape region of the peninsula. Mr. Slevin is accompanied by Mr. Gordon F. Ferris, instructor in entomology of Stanford University. Mr. Ferris is commissioned by Stanford University to make a special study of the scale insects of the region and will also collect for the departments of entomology and invertebrate zoology of the California Academy of Sciences. This work will be chiefly in the lower third of the peninsula and will require about three months time. Dr. Roy E. Dickerson, honorary curator of the Department of Invertebrate Paleontology, sailed May 31 with Mrs. Dickerson for Manila, Philippine Islands. Dr. Dickerson will make an investigation of the Phillippine Islands with a view to the location of oil deposits. During Dr. Dickerson's connection with the California Academy of Sciences as curator of the department of invertebrate paleontology important research work was carried on in the geology of the Pacific coast area, which received publication in the Proceedings of the academy. These papers are much in demand at present by the commercial interests engaged in oil production. FOREIGN DELEGATES AND GUESTS AT THE ATLANTIC CITY MEETING OF THE AMERICAN MEDICAL ASSOCIATION PHYSICIANS from fourteen foreign countries were in attendance at the meeting. Apart from Canadians they were as follows: Lehman, Wilmer S., Lolodorf, Cameroon, W. Casier, Baron Ernest, Belgium. Melis, L., Brussels, Belgium. Peter, William Wesley, Shanghai, China. Fernandez, Francisco M., Havana, Cuba. Somodevilla, Santiago U., San Luis, Cuba. Newsholme, Sir Arthur, England. |